# this file has 27 nodes, 47 edges
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
1 2
1 3
1 4
1 5
5 6
5 7
8 9
8 10
8 5
11 12
11 13
11 8
14 15
14 16
14 11
17 18
17 19
17 14
20 21
20 17
23 24
23 20
25 22
26 25
27 26
27 24
24 25
24 21
22 19
21 22
21 18
19 16
18 19
16 13
15 16
15 12
13 10
12 13
10 7
9 10
9 6
6 7
4 27
4 26
3 26
3 7
2 27
